There is disclosed in the above identified parent applications, and hereinafter herein, a comprehensive architecture and methodology for providing telephony services over hybrid systems of circuit switched and packet switched networks, such as combinations of telephone networks and data networks typified by public switched telephone networks (PSTNs) and the Internet. In order to provide maximum flexibility and usability of such combinations it is desirable to enable and facilitate cooperative usage of the architecture and methodology by multiple service provider entities which supplement one another and which, in many instances, are competitors. This requires that it be possible to provide amongst such entities an acceptable and efficient resource allocation, usage allocation, usage accounting, and billing and settlement arrangement.